This invention relates to air conditioning units and in particular though not solely relates to air conditioning units which in use are mounted through a partition such as a wall or window such that part of the air conditioning unit is positioned outside a building and such that the remainder of the air conditioning unit is positioned within the building such that air can be drawn from inside or outside the building and then conditioned such that the air reaching inside the building provides a more comfortable environment for persons living or working within the building than would otherwise be the case.
Such air conditioning units at present available have been disadvantageous in particular in that the noise level from such air conditioning units and passed into the building is above that which is desirable. This noise arises in central as the component parts of the air conditioning unit are mounted on a chassis positionable within a housing in a manner such that the chassis may be removed in particular for servicing of the component parts. The component parts are usually placed on the chassis such that the evaporator is positioned within the room and such that the compressor and condenser are positioned outside the room. In this arrangement the noise arises principally from the compressor and the fans circulating air over the condenser but such noise is transmitted to the room by means of holes positioned within the chassis to allow air passage into the building and also for services such as refrigeration pipes.
Weather seals between the housing and the chassis also permit sound to enter the room. Sealing strips such as rubber strips along the sides of the chassis are used but this has proved ineffectual and has in fact provided a further noise path for noise arising from the compressor fans and also has provided a noise path for other noise arising outside the building such as traffic noise or other noises.
This problem has been compounded as the chassis generally sits on the bottom surface of a housing passing through the wall or window and the compressor and fans when operating cause the chassis to vibrate thus causing the chassis to knock against the housing giving rise to an uncomfortable and unpleasant noise particularly when metal to metal contact occurs. Attempts to damp such noise have also proved ineffectual.